<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <link rel="stylesheet" href="./test.css">
</head>
<body>
    <div class="flex-demo">
        <ul class="flex-container second">
            <li class="flex-item">1</li>
            <li class="flex-item">2</li>
            <li class="flex-item">3</li>
            <li class="flex-item">4</li>
        </ul>
    </div>
</body>
</html>